Back and neck pain are common conditions that can adversely affect both work and leisure activities. One commonly used non-surgical approach to alleviating back pain in patients is the application of traction forces. Traction tables are used to apply traction forces to the human body through the application of tension force along the spinal column. Traction tables are generally used to relieve pain in two areas, the lumbar region, which is located between a patient's ribs and hipbones, and the cervical region, which corresponds to the patient's neck region.
A traditional system for applying traction to a patient is through the use of weights and pulleys. The method entails placing a patient in the supine position and securing the patient to a resting surface. Cords are then extended from the patient, looped around suspended pulleys and tied to raised weights which are released to provide a gravitational force. The weights thereby apply traction to the patient's back. The system has had only limited success because it does not sufficiently isolate the region of the body to which the force is to be applied. Furthermore, the system does not adequately treat patients with painful postural deformities, for example a flexed, laterally shifted posture often seen in patients suffering from a herniated lumbar disc.
U.S. Pat. No. 4,890,604 (Nelson) discloses a traction assembly that applies traction under the inclined weight of the patient. The traction assembly includes a stationary stand supportable on a ground or floor surface and a table assembly connected to the stand. The table assembly includes a frame that is rotatably assembled to the stand for limited rotation about a horizontal axis. A flat platform or table is slidably assembled to the frame for back-and-forth movement under gravitational influence in a longitudinal direction perpendicular to the axis of rotation of the frame. Restraints are connected to the patient's ankles and head. Upon rotation of the frame on the stand to incline the platform, the body is put in traction according to the weight of the body and the degree of inclination.
One shortcoming of this invention is that the degree of applied force depends upon the weight of the body and the inclination of the frame, rather than by an independent force. Furthermore, the assembly does not compensate for a patient's postural deformities. For example, a patient with a herniated lumbar disc may not be able to lie perfectly straight on the table, reducing the effectiveness of the gravitational force. Further yet, because the patient is anchored to the table at the neck and ankles, the table does not sufficiently concentrate traction force on the specific area in need of treatment, for example the lumbar region of the body.
U.S. Pat. No. 4,995,378 (Dyer et al.) discloses a therapeutic table with a frame and a table top having an upper-body section rigid with respect to the frame, and a lower-body section slidable with respect to the frame. The sections provide a separable surface for a patient to lie prone face down. Hand grips rigid with respect to the upper-body section extend upwardly of the plane of the table top to be accessible by a patient with arms above head along a plane of the axis of the patient's spine to provide anchoring for the upper body. An anchor is connected to the lower-body section to which a pelvic belt can be connected. A cylinder and piston drive is provided to slide the lower-body section to cyclically increase and decrease the distance between the hand grips and the pelvic belt anchors.
Although the Dyer device avoids the use of weights and pulleys, it still requires a cumbersome harness to be placed around the patient that is anchored to the end of the lower-body section of the table. It also requires the patient to lie prone and hold on to hand grips to properly apply the force. The traction force is thus extended along the entirety of the patient's spine, rather than focusing on the lumbar region. Dyer does not disclose a multi-axis traction device that can compensate for patient postural deformities that hinder the application of traction forces along the spine.